Light-sensitive diazotype material

ABSTRACT

DIAZOTYPE MATERIAL HAVING IMPROVED LIGHT-SENSITIVITY AND DEVELOPING SPEED WITH GOOD KEEPING AND EXPOSURE PROPERTIES IS PROVIDED BY UTILIZING IN THE LIGHT-SENSITIVE LAYER A PARA-(TERTIARY) AMINO-2-(FLUORO, CHLORO OR BROMO)-3(FLUORO, CHLORO OR BROMO)-BENZENEDIAZONIUM COMPOUND IN WHICH ONE OF THE TERTIARY AMINO SUBSTITUENTS IS ALKYL OR ARALKYL AND THE OTHER IS ALKYL, ARALKYL OR CYCLOHEXYL, OR IN WHICH SAID SUBSTITUENTS FORM A HETEROCYCLIC RING WITH THE P-AMINO NITROGEN ATOM. THE COMPOUND GIVES ESPECIALLY GOOD LIGHT-SENSITIVITY AND KEEPING QUALITIES WHEN THE PARAAMINO GROUP IS ACYCLIC.

United States Patent Oflice 3,560,215 Patented Feb. 2, 1971 3,560,215LIGHT-SENSITIVE DIAZOTYPE MATERIAL Carel Jacobus Knoester and HubertusJohannes Wilhelmus Pecasse, Venlo, Netherlands, assignors to Van DerGrinten N.V., Venlo, Netherlands No Drawing. Filed July 12, 1967, Ser.No. 652,694 'Claims priority, application Netherlands, July 15, 1966,6610037 Int. Cl. G03c 1/54, 5/34; G07c 113/00 US. CI. 9691 8 ClaimsABSTRACT OF THE DISCLOSURE Diazotype material having improvedlight-sensitivity and developing speed with good keeping and exposureproperties is provided by utilizing in the light-sensitive layer apara-(tertiary) amino-Z-(fluoro, chloro or bromo)-3- (fluoro, chloro orbromo)-benzenediazonium compound in which one of the tertiary aminosubstituents is alkyl or aralkyl and the other is alkyl, aralkyl orcyclohexyl, or in which said substituents form a heterocyclic ring withthe p-amino nitrogen atom. The compound gives especially goodlight-sensitivity and keeping qualities when the paraamino group isacyclic.

The invention relates to light-sensitive diazonium compounds and todiazotype material sensitized therewith. The diazotype material may beso-called one-component diazotype material, which is developed with aliquid containing an azo-coupling component, so-called tWo-compo nentdiazotype material, which is developed with the aid of ammonia vapour,or heat-developable diaztoype material.

For sensitizing one-component diazotype material, benzene diazoniumcompounds having a tertiary amino group such as a diethylamino group ora N-methyl-N-cyclohexylamino group in the para-position and a chlorineatom in the meta-position are used on a large scale. Since diazotypematerials sensitized with these diazonium compounds furnish copies theazo-dyestuff image of which has high U.V.-absorption, these diazoniumcompounds are chiefly used for sensitizing transparent diazotypematerials for making so-called intermediate originals.

British patent specification No. 957,838 describes transparentone-component diazotype material comprising a hydrophilic film layer inwhich has been incorporated a diazonium compound of the general FormulaI:

TTzX in which X is an anion, Y stands for a chlorine or a bromine atom,and Z for a N-alkyl-N-benzylamino, a N-alkyl-N-cyclohexylamino, or adibenzylamino group.

This diazotype material can be developed with weakly acid phloroglucinoldevelopers.

British patent specification No. 972,951 describes onecomponentdiazotype material sensitized with a diazonium compound of the generalFormula II:

I Nmethyl cyclohexyl in which X is an anion, R and R represent chlorineor bromine atoms, and the cyclohexyl group may carry one or more methylgroups. Preferably this diazotype material is transparent diazotypematerial with a light-sensitive hydrophilic film layer. It has higherdeveloping speed than material sensitized with4-diazo-2-chloro-N-methyl- N-cyclohexylaniline. Like the last-mentionedcompound, the diazonium compounds mentioned in British patentspecification No. 972,951 have fair light-sensitivity.

Further compounds mentioned in the literature are the diazoniumcompounds 4-diazo-2,5-dichloro-N-ethyl-N- benzylaniline (see Fiat FinalReport 813, page 1349) and 4-diazo-2-chloro-5-bromo-N,N-dimethylaniline(see Canadian patent specification No. 627,653).

According to the present invention, a new diazotype material is providedwhich comprises a support and, carried on the support, a light-sensitivelayer containing one or more light-sensitive diazonium compounds of thegeneral Formula 111:

in which X is an anion, each of Y and Y is a fluorine, a chlorine or abromine atom, R is an alkyl or an aralkyl group, and R is an alkyl, anaralkyl or a cycloalkyl group, or in which R and R form a saturatedheterocyclic ring with the nitrogen atom to which they are attached. Analkyl group at either R or R may be branched or non-branched, and any ofthe named substitutents at R or R may be substituted or non-substituted.

This new diazotype material has higher light-sensitivity than diazotypematerial sensitized with a corresponding diazonium compound according toBritish patent specifications Nos. 957,838 or 972,951. Moreover, thediazotype material according to the invention has a higher developingspeed and good keeping qualities, and it bleaches out clearly uponexposure.

Especially suitable diazonium compounds are those according to FormulaIII, in which stands for an acyclic amino group. These diazoniumcompounds are more light-sensitive and have greater stability than thecorresponding compounds in which is a heterocyclic group. Consequently,diazotype material sensitized with the former is more light-sensitiveand has better keeping qualities than diazotype material sensi tizedwith the latter.

The diazotype material according to the invention is preferablyone-component diazotype material. It may, however, also betwo-components diazotype material or heat-developable diazotypematerial. (By one-component diazotype material is also to be understooda light-sensitive printing plate which has been sensitized with adiazonium compound according to Formula 111, the formation of theoleophilic image being effected by azo-dyestuff formation.)

The following is a list, though not a complete one, of diazoniumcompounds which can be used with good results in diazotype materialaccording to the invention:

4-diazo-2,3 -difluoro-N,N-dimethylaniline4-diazo-2,3-dibromo-N,N-dimethylaniline4-diazo-2,3-dichloro-N,N-dimethylaniline4-diazo-2,3-dichloro-N,N-diethylaniline4-diazo-2,3-dichloro-N,N-di-n-propylaniline 4-diazo-2,3-dichloro-N,N-di-n-butylaniline4-diazo-2,3-dichloro-N,N-di-n-pentylaniline4-diazo-2,3-dichloro-N,N-di-n-hexylaniline4-diazo-2,3-dichloro-N-methyl-N-isobutylaniline 4-diazo-2,3-dichloro-N-ethyl-N-2'-hydroxyethylani1ine4-diazo-2,3-dichloro-N-ethyl-N-2'-chloroethylaniline4-diazo-2,3-dichloro-N,N-bis (2'-hydroxyethyl) aniline 4-diazo-2,3-dichloro-N-methyl-N-benzylaniline 4-diazo-2,3-dichloro-N-ethyl-N-benzylaniline4-diazo-2,3-dichloro-N-n-propyl-N-benzylaniline4-diazo-2,3-dichloro-N-n-butyl-Nbenzylaniline4-diazo-2,3-dichloro-N-methyl-N-3 ',4'-dichlorobenzylaniline4-diazo-2,3-dichloro-N-methyl-N-cyclohexylaniline4diazo-2,3-dichloro-N-methyl-N-4-methylcyclohexylaniline 4-diazo-2,3-dichloro-N-isobutyl-N-benzylaniline4-diazo-2,3-dichloro-N,N-diisobutylaniline 4-diazo-2,3-dichloro-N-benzyl-N-cyclohexylaniline4-diazo-2,3-dichloro-N-methy1-N-pentylaniline4-diazo-3-bromo-2-chloro-N,N-dimethylaniline4-diazo-2-chloro-3-bromo-N,N-dimethylaniline 4-diazo-3-chloro-2-fluoro-N,N-dimethylaniline 4-diazo-3-fiuoro-2-chloro-N,Ndimethylaniline4-diazo-3-fiuoro-2-bromo-N,N-dimethylaniline4-diazo-3-bromo-2-fluoro-N,N-dimethylaniline N- 4-diazo-2,3-dichlorophenyl morpholine N- (4-diazo-2,3-dichlorophenyl) piperidine N-4-diazo-2,3-dichlorophenyl) pyrrolidine N- (4-diazo-2,3-dichlorophenyl)-N'-acetylpiperazine( 1,4)

The diazonium compounds can be used as diazonium salts, e.g. asdiazonium chloride, nitrate, sulfate, hydrogen sulfate or phosphate, oras diazonium metal chloride double salt, such as chlorozincate,chloromanganate, or chlorostannate, as diazonium borofiuoride or as adiazonium aryl sulfonate.

They can be applied in the diazotype material individually, mixedtogether, or in admixture with diazonium compounds of other types.Accordingly as the diazotype material according to the invention has ahigher content of another diazonium compound it will present thespecific r advantages of the diazonium compounds according to theinvention to a lesser degree.

Using the diazonium compounds according to the invention, theconventional supports, such as paper, tracing paper, printing-platepaper, tracing linen, opaque linen, synthetic paper, metal foils, glassfibre, polyester film and the like, can be sensitized. The diazoniumcompound may or may not be incorporated in a hydrophilic or hydrophobicfilm layer, which, if desired, has been anchored to the support with theaid of one or more intermediate layers.

In the diazotype material according to the invention the conventionalauxiliary agents can be used, e.g. acids, such as citric acid, tartaricacid, boric acid, and phosphoric acid; stabilizers, such as benzene andnaphthalene sulfonic acids, p-phenolsulfonic acid, and theirwater-soluble salts; metal salts, such as zinc chloride, magnesiumchloride, nickel sulfate, and alum; substances which serve to enhancethe developing speed, such as glycerol, polyethylene glycol, urea,thiosinamine, and the like; surfaceimproving substances, such as finelydivided silicium dioxide (colloidal or non-colloidal), aluminium oxide,barium sulfate, rice starch, etc.; binders, such as gelatin, gum arabic,cellulose ethers, starch derivatives, polyvinyl alcohol; dispersions ofsynthetic resins, such as dispersions of cationic, nonionic, and anionicpolyvinyl acetate.

The diazonium compounds according to the invention maybe prepared asfollows:

2,3,4-tri(fluoro, chloro, bromo) nitrobenzene is converted into3,4-di(fiuoro, chloro or bromo) 2-aminonitrobenzene with ammonia in anautoclave. The halogen atom in para-position to the nitro group is thenreplaced by a tertiary amino group by reaction with an amine, the aminogroup in ortho-position to the nitro group is diazotized, and then thediazonium group is replaced by a fluoride, a chlorine or a bromine atomaccording to the Sandmeyer reaction. The 4-tert.amino-3-(fiuoro, chloroor bromo)-2-(fluoro, chloro or bromo) nitrobenzene thus prepared isconverted into a diazonium compound by reduction and diazotization.

Several compounds according to the invention can also be preparedstarting from 2,3-di(fluoro, chloro or bromo)- aniline. This product istosylated and then nitrated to 4- nitro 2,3 di (fluoro, chloro orbromo)-N-tosylaniline, which is alkylated, saponified, and alkylatedagain. Thus 4-dialkylamino-2,3-di-(fluoro, chloro or bromo) nitrobenzeneis obtained, from which the diazonium salt can be prepared by reductionand diazotization.

The phloroglucinol developers which are used in the one-componentdiazotype process often vary as to their composition and acidity. Below,two Weakly acidic phloroglucinol developers and one weakly alkalinephloroglucinol developer are described which are employed in practiceand are used for development in a number of the following examples.

Developer A is a solution of 4 g. of phloroglucinol 0.1 g. ofacetoacetanilide 3 ml. of an aqueous solution of 38% by Weight of sodium2-ethylhexyl sulfate 15 g. of beet sugar 2.5 g. of benzoic acid 14 g. ofsodium benzoate 135 g. of sodium formate in 1000 ml. of water.

The pH of this liquid is approximately 5. 8. Developer B is a solutionof 6.5 g. of phloroglucinol 4 g. of resorcinol 10 g. of thiourea 2 g. ofsodium dibutylnaphthalene sulfonate 14 g. of sodium formate 22 g. ofsodium benzoate 49 g. of trisodium citrate (2 aq.)

1.2 g. of citric acid in 1000 ml. of water.

The pH of this liquid is approximately 6.5. Developer C is a solution of30 g. of thiourea 5.4 g. of phloroglucinol 6.5 g. of resorcinol 1 g. ofpotassium hydroquinone monosulfonate 5 g. of sorbitol 15 g. of beetsugar 50 g. of potassium tetraborate (5 aq.)

1.5 g. of sodium isopropylnaphthalene sulfonate in 1000 ml. of water.

The pH of this liquid is approximately 9.

EXAMPLE I White base paper for the diazotype process of weight g./m. issensitized with a solution containing 13 g. of4-dimethy1amino-3,3-dichlorobenzene diazonium chloride, zinc chloridedouble salt 50 g. of tartaric acid 10 g. of thiourea 10 g. of7-hydroxy-l',2,4,5-naphthimidazole 10ml. of hydrochloric acid (s.g.1.19)

0.2 g. of saponine in 1000 ml. of water and dried.

A sheet of the diazotype material thus obtained is imagewise exposedunderneath an ink drawing on tracing paper until the diazonium compoundunderneath the image-free portions has completely bleached out, and isthen developed in ammonia vapour. The copy thus obtained shows anorange-red image on a white background.

The diazonium compound used according to the example can be prepared asfollows:

2,3-dichloroaniline is tosylated, nitrated, and then brought intoreaction with dimethyl sulfate. The 4-nitro- 2,3 dichloro-N-methyl Ntosylaniline thus obtained is saponified to4-nitro-2,3-dichloro-N-methylaniline, which is then alkylated to4-dimethylamino-2,3-dichloronitrobenzene, which melts at 80 C. From thiscompound the above-mentioned diazonium salt is obtained by reduction anddiazotization.

EXAMPLE II (a) A sheet of white base paper for the diazotype process ofweight 80 g./m. is sensitized with a solution containing 30 g. of4-N-methyl-N-cyclohexylamino-2,3-dichlorobenzene diazonium chloride,stannic chloride double salt 5 g. of tartaric acid 30 ml. of aqueouspolyvinyl acetate dispersion Vinnapas H.60 (from Wacker-Chemie G.m.b.H.,Munich, Germany) in 1000 ml. of 'water and dried.

(b) A sheet of white base paper for the diazotype process of weight 80g./m. is sensitized with a solution containing 30 g. of4-N-methyl-N-cyclohexylamino-2,5-dichlorobenzene diazonium chloride,zinc chloride double salt 5 g. of tartaric acid 30 ml. of aqueouspolyvinyl acetate dispersion Vinnapas in 1000 ml. of water and dried.

(c) A sheet of white base paper for the diazotype process of weight 80g./m. is sensitized with a solution containing 21 g. of4-N-methyl-N-cyclohexylamino-3-chlorobenzene diazonium chloride, zincchloride double salt 5 g. of tartaric acid 30 ml. of aqueous polyvinylacetate dispersion Vinnapas in 1000 ml. of water and dried.

From each sheet a strip is cut. The strips are placed side by side in astep wedge and exposed until, underneath the step with the highestlight-transmission, the diazonium compound on the strip having thelowest light-sensitivity has just bleached out. Then the strips aredeveloped with developer C. The test shows that strip a has the highestlight-sensitivity, strip c has the lowest light-sensitivity.

A second strip of each sheet is exposed underneath an original havinglarge black Well-masking areas, until the diazonium compound underneaththe image-free portions of the original has completely bleached out, andis then developed with developer B. The strips a and b have anapproximately equal developing speed; strip clearly shows a lowerdeveloping speed.

The diazonium compound used according to the Example II(a) can beprepared as follows:

2,3,4 trichloronitrobenzene is brought into reaction with ammonia in anautoclave and then converted with N-methylcyclohexylamine into4-N-methyl-N-cyclohexylamino-3-chloro-2-aminonitrobenzene, whichcompound is converted, by diazotization and the Sandmeyer reaction, into4-N-methyl-N-cyclohexylamin0 2,3-dichloronitroben zene, which melts at78 C. From this compound the above-mentioned diazonium salt is obtainedby reduction and diazotization.

6 EXAMPLE III Tracing linen of weight 80 g./m. is sensitized with asolution containing 45 g. of 4-di-n-butylamino-2,3-dichlorobenzenediazonium chloride, stannic chloride double salt 5 g. of tartaric acid300 ml. of ethanol (96%) 700 ml. of water 10 and dried.

A sheet of the transparent diazotype paper thus obtained is imagewiseexposed underneath a pencil drawing on tracing paper until underneaththe image-free portions of the drawing the diazonium compound haslargely bleached out, and is then developed with developer B.

The copy shows a dark image on a foggy brown-grey background. It may beused as an intermediate original for further copying on diazotypematerial.

The diazonium compound used according to the example can be prepared asfollows:

EXAMPLE IV White base paper for the diazotype process of weight 80 g./m.is sensitized with a solution containing 28 g. of4-N-methyl-N-benzylamino-2,3-dichlorobenzene diazonium chloride, stannicchloride double salt 5 g. of citric acid 30 ml. of Vinnapas H60 in 1000ml. of Water and dried.

A sheet of the diazotype paper thus obtained is imagewise exposed as inExample III and developed with developer A.

The copy shows a dark violet-brown image on a foggy background.

The diazonium compound used according to the eX- ample can be preparedas follows:

3,4-dichloro-2-aminonitrobenzene is brought into reaction withN-methylbenzylamine and then diazotized and treated by the Sandmeyerreaction to give 4-N-methyl-N- benzylamino-2,3-dichloronitrobenzene,which melts at 65-66 C. From this compound the above-mentioned diazoniumsalt is prepared by reduction and diazotization.

EXAMPLE V Sized natural tracing paper of weight g./m. is sensitized witha solution containing 27 g. of 4-morpholino-2,3-dichlorobenzenediazonium chloride, zinc chloride double salt 30 g. of sodiumnaphthalene-1,3,6-trisulfonate 5 g. of tartaric acid 100 m1. of ethanol(96%) 900 ml. of water and dried.

A sheet of the transparent diazotype paper thus obtained is imagewiseexposed and developed as in Example III. The copy shows a red-brownazo-dyestufl image on a foggy background. The copy can be used as anintermediate original for making further copies on diazotype material.

The diazonium compound used according to the example can be prepared asfollows:

3,4-dichloro-2-aminonitrobenzene is brought into reaction withmorpholine and then diazotized and by the Sandmeyer reaction convertedto 4-morpholino-2,3-dichloronitrobenzene, which melts at C. From thiscompound the above-mentioned diazonium salt is prepared by reduction anddiazotization.

7 EXAMPLE VI A planographic paper printing plate of the type Rota printC3 is sensitized with a solution containing 30 g. of4-N-methyl-N-benzylaminc-2,3-dichlorobenzene diazonium chloride, zincchloride double salt 200 ml. of ethanol (96%) 800 ml. of water anddried.

The light-sensitive printing plate has good keeping qualities. It isimagewise exposed underneath a transparent ink drawing until thediazonium compound underneath the image-free portions of the drawing hascompletely bleached out. The image on the printing plate is developed bymoistening the image side of the plate with a solution of 12 g. ofphloroglucinol 11 g. of citric acid 87 g. of disodium phosphate 2 aq.

in 1000 ml. of water.

Then the plate is sponged down with water. The plate shows a blackimage, which absorbs ink quite selectively. From the plate 50 goodoffset prints can be made.

EXAMPLE VII White base paper for the diazotype process of weight 80g./m. is sensitized with a solution containing 20 g. of4-dimethylamino-3-fluoro-2-chlorobenzene diazonium chloride, stannicchloride double salt g. of citric acid 30 ml. of Vinnapas H.60

in 1000 ml. of water and dried.

A sheet of the diazotype paper thus obtained is imagewise eXposed-asinExample III and developed with developer C.

The copy shows a brown image on a foggy background.

The diazonium compound used according to the example can be prepared asfollows:

3-chloro-2-fluoro-l-nitrobenzene is reduced to 3-chloro-2-fiuoroaniline. This product is tosylated. The tosylamino compound isnitrated, methylated and saponified. The4-methylamino-3-fiuoro-2-chloro-l-nitrobenzene thus obtained ismethylated. From the nitro compound thus produced (M.P. 102 C.) theabove diazonium salt is obtained by reduction and diazotization.

EXAMPLE VIII White base paper for the diazotype process of weight 80g./m. is sensitized with a solution containing 22 g. of4-dimethylamino-3-bromo-2-chlorobenzene diazonium chloride, stannicchloride double salt 5 g. of citric acid 30 ml. of Vinnapas H.60

in 1000 ml. of water and dried.

A sheet of the diazotype paper thus obtained is imagewise exposed as inExample III and developed with developer C.

The copy shows a brown image on a foggy background.

The diazonium compound .used according to the example can be prepared asfollows:

2,3-dichloro-l-nitrobenzene is converted with ammonia inan autoclaveinto 3-chloro-2-aminonitrobenzene. This product is diazotized and by theSandmeyer reaction converted into 3-chloro-2-bromo-l-nitrobenzene. Thisproduct is reduced to 3-chloro-2-bromoaniline which is tosylated. Thetosylamino compound is nitrated, methylated and saponified. The4-methyl-3-bromo-2-ehloro-l-nitrobenzene thus obtained is methylated.From the nitro compound thus produced (M.P. 212 C.) the above diazoniumsalt is obtained by reduction and diazotization.

What is claimed is:

1. A light-sensitive diazonium compound of the formula wherein: X is ananion; Y is a fluorine, chlorine or bromine atom; Y is a fluorine,chlorine or bromine atom; R is an alkyl or aralkyl group; and R is analkyl, aralkyl or cycloalkyl group; or R and R together form a saturatedfiveor six-membered heterocyclic ring with the notrogen atom towhichthey are attached.

2. Diazotype material Which comprises a support and, carried thereon, alight-sensitive layer containing a lightsensitive diazonium compound asdefined in claim 1.

3. Diazotype material according to claim 2, wherein R is an alkyl oraralkyl group and R is an alkyl, aralkyl or cycloalkyl group.

4. Diazotype material according to claim 2, wherein one of R and R is acyclohexyl group.

5. Diazotype material according to claim 2, wherein said diazo compoundis a 4-N-alkyl-N-cyclohexylamino- 2,3-dichlorobenzene diazonium salt.

6. A process for the production of a diazotype record which comprisesimagewise exposing a diazotype material as defined in claim 1 anddeveloping the product with a phloroglucinol developer.

7. A process for the production of a diazotype record which comprisesimagewise exposing a diazotype material as defined in claim 2 anddeveloping the product with a phloroglucinol developer.

8. A light-sensitive diazonium compound according to claim 1, namely, a4-N-alkyl-N-cyclohexylamino 2,3-dichlorobenzene diazonium salt.

References Cited UNITED STATES PATENTS 9/1929 Schirmacher et a1. 260-441l/1937 Schnitzspahn et a1. 260-141 US. Cl. X.R.

